In June 2025 I upgraded my K1 Max with the Creality CFS upgrade kit. As my K1 Max had the older Hot End I also upgraded that with the Ceramic Hot End upgrade kit with the unicorn nozzle. I have been delighted with the results until a week ago. I kept getting a cutter error so I removed the extruder to have a look. I noticed that the rubber boot on the Hot End was badly discoloured and so decided to investigate. The rubber boot was solid - not flexible. In trying to remove it the two copper thermistor cables came away from the body of the hot end. Only solution was to replace the Hot End again. I noticed that there had been a leak into the rubber boot which had been the cause of it going solid. On checking the unicorn nozzle I discovered it was loose. When the “new” Ceramic Hot End Upgrade kit arrived I decided to check the unicorn nozzle before fitting the kit. Surprise, surprise - this was loose as well. Nowhere in the fitting instructions does it mention to check that the unicorn nozzle is tight before fitting the combined heat sink and Hot End. Have I been very unlucky TWICE or should the fitting instructions include a step to check this or is this a manufacturing issue? All is now back up and running and printing well. Paul